Apparatus for casting sheets or films



sept. 1o, 1935. E, BLEIBLER 2,013,978

APPARATUS FOR CASTING SHEETS OR FILMS Filed NOV. lO, 1934 y 2 Sheets-$heet l .gf si 26e/ U /78 A115 30 f 3o l /29 Figi 42V. n' 45 #1g/ /43 Illll'lIIllLl /NvfI/vm? fswfsr BLE/54E@ ATTORNEY Septo 10, 1935.

E. BLEIBLER APPARATUS FOR CASTING SHEETS OR FILMS Filed NOV. lO, 1954 2 Sheets-Sheet 2 [NVE/wok ERNEST BLE/'BLM V ,er fmful,

AYI'ORNEY Patented Sept. 10, 1935 UNITED STATES PATENT OFFICE APPARATUS FoacAs'rING SHEETS on.

FILMS Ernest Bleibler, Ghent, Belgium, assigner to Sylvania Industrial Corporation, Fredericksburg, Va., a corporation of Virginia Application November 10, 1934, Serial No. '752,479 In Great Britain November 6, 1933 9 Claims.

per is continuously renewed with certainty, allv parts thereof passing from the point where it enters to the slit of the hopper, withoutV any stagnating parts of it being able to coagulate and so give rise to the choking up of the apparatus or 10 other hindrances to the working thereof.

It is a further object of the invention to enable the viscose, which is supplied under the pressure of the viscose pump or by other means, e. g. compressed air, to tranquilize itself and to afford to l5r gas or air opportunity to separate and collect apart from the viscose, so that the viscose inside the hopper space is completely free from gas or air.

Another object of the invention is to give al- 20 lowance for the varying amount of shrinking vwhich takes place over the width of the band regenerated from the viscose.

It is a further object of the invention to supply the viscose to the hopper without using any 25 movable parts in the conduit, while the hopper itself is tiltable.

Still a further object of the invention refers to means which permit to observe accurately and to adjust the pressure gauge of the viscose. 30 According to the invention the casting apparatus for sheets or iilms is characterized by the fact that within the hopper above the pouring slit there are arranged conduit means for sup` plying the viscose in an ascending stream or 35V streams, a free space being arranged in the upper part of the hopper to which upper part the viscose is delivered, the said conduit means eX- posing the Surface of the Viscose to the space within the said chamber before the viscose sinks 40 down to the extruding slit, whereby air or gas included in the viscose separate into said space. Thus, the viscose is continuously renewed with certainty, and without any risk of any stagnating parts being able to coagulate and thus to choke 45 up the apparatus.

" This advantageous structure for feeding the viscose is assisted if, according to a preferred constructional form of the subject-matter of the invention, the conduit means terminate in a par- 50 t tition which extends towards the highest point of the hopper space.

The viscose, which is supplied under the pres-l sure of the viscose pump or other means, e. g. compressed air, is able to tranquilize itself and 55,1 gas or air are afforded opportunityto separate and collect in the highest part of the hopper space, so that the viscose inside the hopper space which is really bounded by the partition is completely free from gas and air.

It is preferable to employ as a casting appa- I5- ratus one made of a non-rusting material for example, as is known per se. Preferably also the outlet slit-is adjustable in respect of its width, as hitherto known, and moreover, is adjustable in respect of its shape. In this way, the varying amount of shrinkage which takes placeover the width of the band regenerated from the viscose can be allowed for. In the embodiment of this part of the invention one or both lips of the hopper are made adjustable transversely so as to enable the width of the slit to be regulated, while for the purpose of regulating the shape, one or both lips ofthe hopper are made to bend, as will hereinafter vbe lmore particularly described.

If thevcasting apparatus be made to oscillate 20 about the hollow shaft which serves simultaneously toV supply the, viscose, important advantages are gained inasmuch as the viscose delivering conduits of the hopper can be packed in a convenient manner by means of the usual packings. The additional advantage-is also gained that no moving parts are necessary to supply the viscose to the casting apparatus. By adjust-Y ing the adjustable lip and suitably tilting the hopper it is possible without any complicated adjusting means to make allowance for the particular conditions necessary in respect of the thickness and velocity of the sheet or film to be coagulated and issuing from the casting apparatus.

This exact adjustment of the thin film of viscose issuing from the casting apparatus can be stillfurther assisted if in the further develop'- ment of the present invention the hopper be provided at its highest point with a chamber for the 40 separation of air or gases fromv the viscose and provided preferably with Sight holes. This chamber may serve, according to another embodiment of this invention, in particular for the reception of anintermediate fluid, inert in particular towards viscose and leading throughr a pipe to the pressure gauge'. By the interpolation of an intermediate medium between the viscose and the pressure gauge the advantage is gained that the pressure of the viscose can be accurately l measured and therefore adjusted at any time, in contra-distinction to arrangements in whichy the viscose itself acts on the pressure gauge. In this arrangement there is risk that should there be any leakage betweenthe' viscose and the pres- 55V sure chamber the viscose will get into the pressure gauge or into the guard liquid, e. g. oil for the pressure gauge and will stay there and as the viscose does not run but remains quiescent it will easily coagulate and render the pressure gauge useless especially in summer time. The interpolation of the inert fluid between the viscose and the pressure gauge therefore prevents such a sensitive instrument as the pressure gauge having to be used directly over the coagulation bath and such wear and tear of the gauge is avoided. The interpolation of an inert fluid between the viscose and the pressure gauge consequently permits the pressure of the viscose being accurately observed while the machine is at work, so that it can be accurately adjusted to the rate at which the machine is to work, to the width of the outlet slit, to the speed at which it issues therefrom, to the composition, the ripeness and toughness of the viscose and also to the temperature or the viscose and the precipitating bath including the composition of this latter.

The invention further comprises a safety valve and pressure gauge consisting of a manometric vessel containing an observation liquid, such vessel containing two ascension pipes staggered relatively to each other vertically, of which one opens near the bottom of the nianometric vessel and at the bottom of an upper vessel, the second, of glass or transparent material or the like, opens as a measuring pipe below and in the vicinity of the arbitrary level in the manometric vessel and in the upper part of the upper vessel, which has in this upper part an air outlet opening.

The invention will be best understood on referring to the drawings aiixed to my specification and forming part thereof which illustrate the invention as embodied in va number of constructions. It will be readily understood, however, that my invention is by no means limited to these constructions and that the scope of my invention and the ambit of my appended claims extends to any construction incorporating the broad principle underlying my invention.

In the drawings:

Fig. l shows in longitudinal section and Fig. 2 in transverse section, the spinning nozzle according to this invention.

Fig. 3 shows in vertical section a constructional example of a pressure indicating device With a safety valve.

Fig. 4 shows, diagrammatically, a form of the adjustable hopper outlet according to this invention.

Figs. 5 and 6 show in transverse section and elevation from below .a constructional form for the adjustment of the outlet slit both as to width and shape, and

Fig. 7 shows a detail.

The casting apparatus is denoted by il. The upper hopper chamber is constructed in a domelike shape by suitable formation of the upper boundary wall 39 of the hopper and rises towards the centre and upwards, the viscose being delivered to the upper part thereof. The lips of the casting apparatus of which both or only one are movable transversely and/or bendable as will be subsequently described with reference to Figs. 4 :to 7, which are preferably of a non-rusting material, are denoted by I4. The pipes l2, I3 are inserted in suitable sleeves l5, which may be provided with packing devices il, and thus form a hollow shaft about which the hopper il can be tilted. In the hopper chamber below the upper pipes l2, i3 are provided conduit-forming partitions 3l rising obliquely towards the centre of the cap or dome-like upper part of the hopper,

so that the viscose entering from the pipes l2, i3 flows over the partitions 3l towards the central upper part of the hopper, is tranquilized on its 5 way thereto and air or gas bubbles separate during this period and collect in the upper part of the hopper. The viscose, freed from gas and air bubbles distributes itself from the opening 32 between the partitions 3l uniformly over the width 10 and length of the hopper and flows in a homogeneous gas and air free mass and at a uniform rate of speed to the opening 29 of the hopper (see Fig. 2). Along this path no corners are present to arrest the even iiow of the viscose, nor are 15 there any recesses into which it could run and give rise to choking up of the machine or other disturbances in the flow of the viscose to the opening of the hopper.

At the highest point of the nozzle a cylindri- 20 cal chamber for example is provided, in which the gas or air contained in the viscose can co1- lect. This cylindrical chamber i8 may be provided with sight holes 25 on opposite sides thereof which may be closed by transparent panes of 25 glass, and which permit what is happening in the chamber i8 to be watched.

ln a further development of the invention the chamber may serve for the reception of an intermediate uid which is inert towards viscose, 30 such as air for example or another gas or even a suitable liquid which serves to connect the hop. per space to a pressure gauge 24 through the pipe 23. To shut oi this pipe a valve 22 is provided. At or in the vicinity of the highest point of the 352 upper part of the hopper and preferably at the foot of the chamber E8 an outlet 35 having aV valve is provided by which the inert fiuid. contained in the chamber or even viscose should it be necessary, can be run oi. L10i A pipe 2E with a valve i9 mayserve to remove air or gas from the chamber I8 or to introduce the intermediate medium also or even to connectthe chamber i3 to a second pressure gauge.

Fig. 3 shows a pressure gauge 25 such as is 451 suitable for a casting apparatus particularly one according to this invention. This device permits of a simple connection being made with a safety? valve. It consists of a manometric vessel 4D, which is filled to a suitable height il with an in- 50 dicating liquid such as coloured water for example. The manometric vessel has two ascension pipes 62, the respective levels of which are staggered, so that the one 43, opens near the bottom lil of the manometric vessel 40 on the 55 one hand and at the bottom of an upper vessel 5G. The second ascension pipe 42 opens below and near the arbitrary level H of the manometric vessel on the one hand and on the other hand in the upper part 5| of the upper vessel. 60 This upper vessel has in its upper part also an air outlet opening 52. The ascension pipe 42 or both ascension pipes also are provided with a scale for reading off the pressure.

If now for any reason the pressure in the head 65 of the hopper rises, the level fl! falls below the lower mouth of the pipe 42, so that the intermediate medium, say air for example, can pass out of the pipe 23 directly into the ascension pipe 2 and now ejects the indicating liquid contained 70 therein upwards out through the upper openings 48. The liquid collects at the bottom of the upper vessel and flows through the pipe 43 back aga-in. A baille 53 arranged between the mouth 4S and the air outlet pipe 52 prevents the meas- 75 uring liquid from being ejected through the air outlet opening. The excess of pressure can now escape unimpeded through the ascension pipe 42, the mouth A8, and the air outlet 52. If the upper vessel be composed of glass or other transparent material, the process of ejection of the liquid can be watched and the manin charge of the hopper can therefore take precautionary measures at once.

In order to make allowance for the varying degree of shrinkage which takes place over the width of the band, Figs. to 7 show an arrangement which permits of the outlet slit of the hopper being adjusted both as regards width and shape. For example, the slit may be given the shape shown in Fig. ll, which allows of a larger quantity of viscose to pass at the middle than at the edges, so that at the end after the band has dried a uniform thickness of the band is obtained and undesirable stresses at the edges are avoided.

In the example shown in Figs. 5 to 7 a transversely movable lip is arranged on the cheek 6U while the lip 53 of the cheek 5! can be bent. This transverse movement is produced by means of screws 65 operated by hand wheels 66 for example and which are adjustable by means of screw threads in a projection or a rib 6l on the cheek. The bolts c5 have on their other ends a round head 68, which rotates freely in a recess $59 in the lip 52, and is secured there by a bipartite rib or other covering Il), 'll which prevents it from moving out of place as shown on a. large scale in Fig. '7.

The lip 62 is also secured by screws 13 which f engage by screw threads in the anges of the cheeks Si! and the stems of which pass through slots 'lll in the lip $2, which permit of a transverse movement thereof.

To enable the lip 63 to bend it is made flexible, its limb i8 being thin transversely and comparatively long vertically. This limb is produced by a recess or groove Sil in the foot 8i of the hopper wall 6i. The groove or recess 80 is on the other hand bounded by a rigid rib 82 on the foot 8l of the wall opposite the limb 18 of the lip. Between the limb 18 of the lip and the rib 82 are placed tension screws 84 and clamping screws 85, which are arranged alternately in considerable number on the lip. By moving the lip 62 transversely and bending the lip 63 the width and shape of the outlet slit of the hopper can be adjusted as may be desired to correspond to the particular conditions and working requirements of the moment.

Since various modifications and different embodiments of the apparatus may be made without transcending the teachings of the invention, it is to be understood that the invention is not limited except as indicated in the appended claims.

I claim as my invention:-

1. In an apparatus for casting sheets or films, the combination of a hopper for a nlm-forming material having an extrusion slit in the lower portion thereof, said hopper being so constructed and arranged as to provide a gas-collecting means at the upper portion thereof above the nlm-forming material, and means for introducing nlm-forming material in an ascending stream into said hopper above said slit and below said gas-collecting means, whereby gas entrapped in the nlm-forming material may escape to said gas-collecting means before the filmforming material sinks down and passes through said extrusion slit.

2. In an apparatus for casting sheets or lms, the combination of a hopper for a nlm-forming material having an extrusion slit in the lower portion thereof and a chamber positioned above and communicating with said hopper, andmeans 5 for introducing the nlm-forming material into said hopper above said slit, said introducing means terminating adjacent the opening between said `chamber and said hopper whereby gas entrapped in the film-forming material may 10 escape to said chamber before the film-forming material sinks down and passes through said extrusion slit.

3. In an apparatus for casting sheets or films, the combination of a hopper for a film-forming material having an extrusion slit therein adjae cent the lower portion thereof, said hopper being so constructed and arranged as to provide a gascollecting means above the nlm-forming material in said hopper, and means for introducing the film-forming material into said hopper, said means comprising an upwardly-extending conduit terminating adjacent said gas-collecting means whereby gas entrapped in the film-forming material may escape to said gas-collecting means before the film-forming material sinks down and passes through said extrusion slit.

4. In an apparatus for casting sheets or films, the combination of a hopper for a film-forming material having an extrusion slit adjacent the lower portion thereof, said hopper being so constructed and arranged as to provide a gas-collecting means above the film-forming material in said hopper, an upwardly-extending partition in said hopper forming the inferior border of a conduit for the film-forming material in said hopper, said partition terminating adjacent said gas-collecting means, whereby gas entrapped in said film-forming material may escape to said gas-collecting means before the nlm-forming material sinks down and passes through said extrusion slit.

5. In an apparatus for casting sheets or films the combination of a hopper for a film-forming material having an extrusion slit at the lower portion thereof, an upper covering for said hopper, said upper covering having an upward extension dening a gas-collecting means communicating with the interior of said hopper, a conduit for introducing nlm-forming material extending upwardly through said hopper and terminating adjacent the lower portion of said gas-collecting means, whereby film-forming material introduced into 4said hopper through said conduit may release entrapped gases into said gas-collecting means before falling into said hopper.

6. In an apparatus for casting sheets or films, the combination of a hopper for nlm-forming material having an extrusion slit in the bottom thereof, said hopper being so constructed and arranged as to provide a gas collecting means at the upper portion thereof, means for introducing film-forming material into said hopper in an ascending stream to a point adjacent said gascollecting means where said nlm-forming material may then sink into the lower part of said hopper, and means for indicating the pressure of film-forming material in said hopper, said means comprising a pressure gauge connected with said gas-collecting means and a fluid which is inert with respect to said nlm-forming material disposed between said gauge and the filmforming material in said hopper.

'7. In an apparatus for casting sheets or iilms, 75

the combination of a hopper for film-forming materials being so constructed and arranged as to provide a gas-collecting means in the upper portion thereof, means for introducing lmforming materials into said hopper, said means extending upwardly through said hopper and terminating adjacent said gas-collecting means, the lower portion of said hopper Walls terminating in lips defining an extrusion slit, which is adjustable with respect to width and shape.

8. In an apparatus for casting sheets or lms, the combination of a hopper for film-forming materials being so constructed and arranged as to provide a gas-collecting means in the upper A portion thereof, a conduit extending upwardly in said hopper and terminating adjacent said gascollecting means and adapted to introduce filmforming materials into said hopper in an as- .cending stream, the lower portion of said hopper walls terminating in lips defining an extrusion slit, at least one of said walls being exible in part whereby it may be bent to vary the shape of the slit.

9. In an apparatus for casting sheets or films, the combination of a hopper for a film-forming material having an extrusion slit in the lower portion thereof, an upwardly-extending partition in said hopper between the upper and lower portions thereof, said partition forming the inferior border of a conduit which introduces lrnforming material into said hopper, said partition terminating with an opening therein in the highest part thereof, wherethrough the nlm-forming material sinks down and passes to and through said extrusion slit, whereby gas entrapped in the nlm-forming material may escape to the space above said partition.

ERNEST BLEIBLER. 

